1. Field of the Invention
The invention relates to a carrier and more particularly, to a package carrier.
2. Description of Related Art
A chip package provides a chip with proper signal and heat transmission paths and protects the chip structure. A leadframe often serves as a carrier of the chip when a conventional wire bonding technique is applied. As contact density in the chip gradually increases, the leadframe is no longer able to further improve the contact density and thus can be replaced by a package carrier which can achieve favorable contact density. Besides, the chip is packaged onto the package carrier by conductive media, such as metal conductive wires or bumps.
Generally, in order to form the package carrier, a core dielectric layer often serves as a core material, and patterned circuit layers and patterned dielectric layers are alternately stacked on the core dielectric layer by performing a fully additive process, a semi-additive process, a subtractive process, or any other process. Consequently, the core dielectric layer accounts for a great proportion of the whole thickness of the package carrier. If the thickness of the core dielectric layer cannot be effectively reduced, it will be very difficult to reduce the thickness of the chip package.